Playbar displays intermittently on tablet (android and ipad) when switched off

I'm using 12.6.0.63 and the playbar is switched off within my project - which has been published and loaded to my LMS.

Upon testing - I have no playbar on desktop - as designed

On Tablet I have a playbar intermittently throughout the slides that comes and goes.

The learners need to complete all slides and listen to the audio content before proceeding to the next slide - hence my own custom navigation. Unfortunately much as the custom navigation works well - it's over-ridden by the playbar. Help!!!!!